There are high expectations regarding utilization of pattern transfer techniques that employ a nanoimprinting method to transfer patterns onto curable resin coated on objects to be processed, in applications to produce magnetic recording media such as DTM (Discrete Track Media) and BPM (Bit Patterned Media) and semiconductor devices.
The nanoimprinting method is a development of the well known embossing technique employed to produce optical discs. In the nanoimprinting method, a mold (commonly referred to as a mold, a stamper, or a template), on which a pattern of protrusions and recesses is formed, is pressed against curable resin coated on a substrate, which is an object to be processed. Pressing of the original onto the curable resin causes the curable resin to mechanically deform or to flow, to precisely transfer the fine pattern. If a mold is produced once, nano level fine structures can be repeatedly molded in a simple manner. Therefore, the nanoimprinting method is an economical transfer technique that produces very little harmful waste and discharge. Therefore, there are high expectations with regard to application of the nanoimprinting method in various fields.
Accompanying refinements in patterns of protrusions and recesses, it is an important objective to improve the release properties between molds and curable resin, from the viewpoint of pattern formation properties (the ease with which patterns of protrusions and recesses can be formed according to the designs thereof in the curable resin).
Methods in which mold release layers are formed to reduce the adhesive force between molds and curable resin to improve the release properties are being utilized. Methods for forming the mold release layers can be broadly divided into wet processes and dry processes.
Methods that employ the wet process immerse molds into solutions in which mold release agents such as silane coupling agents are dissolved, and cause the mold release agents to chemically react with the surfaces of the molds. Methods that employ the wet process require sufficient immersion time and a rinsing step after the immersion step. Therefore, such methods require several ten minutes to several hours as a whole, and there is a problem that throughput in mold production deteriorates.
Meanwhile, methods that employ the dry process form deposited films onto patterns of protrusions and recesses on molds by deposition methods such as the CVD (Chemical Vapor Deposition) method. In methods that employ the dry process, a series of steps (etching of substrates, asking, etc.) can form the deposited film using the same apparatus, and therefore it is expected that methods that employ the dry process can improve throughput over methods that employ the wet process.
Examples of methods that employ the dry process are disclosed in U.S. Patent Application Publication No. 20100055346 and M. Okada et al., “Nanoimprinting Using Plasma Chemical Vapor Deposition Film using Mixture Gas with CHF3 and O2 Gases Formed on Mold”, Extended Abstract of the 56th JSAP Spring Meeting 2009, Vol. 2, p. 727, 2009, for example. U.S. Patent Application Publication No. 20100055346 discloses that a deposited fluorocarbon film is formed on a pattern of protrusions and recesses of a Ni mold. M. Okada et al., “Nanoimprinting Using Plasma Chemical Vapor Deposition Film using Mixture Gas with CHF3 and O2 Gases Formed on Mold”, Extended Abstract of the 56th JSAP Spring Meeting 2009, Vol. 2, p. 727, 2009 discloses that a deposited fluorocarbon film is formed on a pattern of protrusions and recesses of a quartz mold by a reactive ion etching technique employing a CVD apparatus.